Android - drawable with rounded corners at the top only

Try to do something like this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:bottom="-20dp" android:left="-20dp">
        <shape android:shape="rectangle">
            <solid android:color="@color/white" />

            <corners android:radius="20dp" />
        </shape>
    </item>
</layer-list>

It seems does not suitable to set different corner radius of rectangle. So you can use this hack.

Try giving these values:

 <corners android:topLeftRadius="6dp" android:topRightRadius="6dp"
         android:bottomLeftRadius="0.1dp" android:bottomRightRadius="0.1dp"/>

Note that I have changed 0dp to 0.1dp.

EDIT: See Aleks G comment below for a cleaner version